At a particular temperature, the half-life of a zero-order reaction is 21.0 min. How long will it take for the reactant concentration to be depleted by a factor of 8?

Question

Quizplus · Accepted Answer

In zero-order reactions, the rate of the reaction is independent of the concentration of the reactant. Hence, the half-life of the reaction is constant. 
t1/2 = 21.0 min
We want to find the time it takes for the reactant concentration to be depleted by a factor of 8.
The factor by which the concentration changes is 2^3 = 8.
Since t1/2 = 21.0 min, the time it takes for the concentration to change by a factor of 8 is:
t = t1/2 x log(8)/log(2)
t = 21.0 x 3.0
t = 63.0 min
Therefore, the answer is C.

At a Particular Temperature, the Half-Life of a Zero-Order Reaction